21.2 Delirium
697
groups or adjusted scores based on normative samples. The clini-
cian seeking neuropsychological consultation should understand
enough about the strengths and weaknesses of selected proce-
dures to benefit fully from the results obtained.
R
eferences
Balzer D. Neurocognitive disorders in DSM-5.
Am J Psych.
2013;170:585.
Blanc-Lapierre A, Bouvier G, Gruber A, Leffondré K, Lebailly P, Fabrigoule C,
Baldi I. Cognitive disorders and occupational exposure to organophosphates:
Results from the PHYTONER Study.
Am J Epidemiol.
2013;177:1086.
Bugnicourt J-M, Godefroy O, Chillon J-M, Choukroun G, Massy ZA. Cognitive
disorders and dementia in CKD: The neglected kidney-brain axis.
J Am Soc
Nephrol.
2013;24:353.
Bugnicourt J-M, Guegan-Massardier E, Roussel M, Martinaud O, Canaple S,
Triquenot-Bagan A, Wallon D, Lamy C, Leclercq C, Hannequin D, Godefroy
O. Cognitive impairment after cerebral venous thrombosis: A two-center study.
J Neurol.
2013;260:1324.
Fields J, Dumaop W, Langford TD, Rockenstein E, Masliah E. Role of neuro-
trophic factor alterations in the neurodegenerative process in HIV associated
neurocognitive disorders.
J Neuroimmune Pharmacol
. 2014;9(2):102–116.
Jack CR Jr, Lowe VJ, Senjem ML, Weigand SD, Kemp BJ.
11
C PiB and structural
MRI provide complementary information in imaging of Alzheimer’s disease
and amnestic mild cognitive impairment.
Brain.
2008;131:665.
Launer LJ. Epidemiologic insight into blood pressure and cognitive disorders. In:
Yaffe K, ed.
Chronic Medical Disease and Cognitive Aging: Toward a Healthy
Body and Brain.
NewYork: Oxford University Press; 2013:1.
Mayeux R, Reitz C, BrickmanAM, Haan MN, Manly JJ, Glymour MM, Weiss CC,
Yaffe K, Middleton L, Hendrie HC, Warren LH, Hayden KM, Welsh-Bohmer
KA, Breitner JCS, Morris JC. Operationalizing diagnostic criteria for Alzheim-
er’s disease and other age-related cognitive impairment—Part 1.
Alzheimer’s
Demen.
2011;7:15.
Schneider JA, Arvanitakis Z, Bang W, Bennett DA. Mixed brain pathologies
account for most dementia cases in community-dwelling older persons.
Neurol-
ogy.
2007;69:2197.
Sonnen JA, Larson EB, Crane PK, Haneuse S, Li G. Pathological correlates of
dementia in a longitudinal, population-based sample of aging.
Ann Neurol.
2007;62:406.
Sweet RA. Cognitive disorders: Introduction. In: Sadock BJ, Sadock VA, Ruiz P,
eds.
Kaplan & Sadock’s Comprehensive Textbook of Psychiatry.
9
th
ed. Philadel-
phia Lippincott Williams & Wilkins; 2009:1152.
Verdelho A, Madureira S, Moleiro C, Ferro JM, Santos CO, Erkinjuntti T, Pantoni
L, Fazekas F, Visser M, Waldemar G, Wallin A, Hennerici M, Inzitari D. White
matter changes and diabetes predict cognitive decline in the elderly: The LADIS
study.
Neurology.
2010;75(2):160.
Weiner MF. Cognitive disorders as psychobiological processes. In: Weiner MF,
Lipton AM.
The American Psychiatric Publishing Textbook of Alzheimer Dis-
ease and Other Dementias.
Arlington, VA: American Psychiatric Publishing;
2009:137.
Zarit SH, Zarit JM. Disorders of aging: Delirium, dementia and other cognitive
problems. In: Zarit SH, Zarit JM.
Mental Disorders in Older Adults: Fun-
damentals of Assessment and Treatment.
2
nd
ed. New York: Guilford Press;
2007:40.
▲▲
21.2 Delirium
Delirium
is characterized by an acute decline in both the level
of consciousness and cognition with particular impairment in
attention. A life threatening, yet potentially reversible disorder
of the central nervous system (CNS), delirium often involves
perceptual disturbances, abnormal psychomotor activity, and
sleep cycle impairment. Delirium is often underrecognized by
health care workers. Part of the problem is that the syndrome
has a variety of other names (Table 21.2-1).
The hallmark symptom of delirium is an impairment of
consciousness, usually occurring in association with global
impairments of cognitive functions. Abnormalities of mood,
perception, and behavior are common psychiatric symptoms.
Tremor, asterixis, nystagmus, incoordination, and urinary
incontinence are common neurological symptoms. Classically,
delirium has a sudden onset (hours or days), a brief and fluc-
tuating course, and rapid improvement when the causative
factor is identified and eliminated, but each of these character-
istic features can vary in individual patients. Physicians must
recognize delirium to identify and treat the underlying cause
and to avert the development of delirium-related complica-
tions such as accidental injury because of the patient’s clouded
consciousness.
Epidemiology
Delirium is a common disorder, with most incidence and prev-
alence rates reported in elderly adults. In community studies,
1 percent of elderly persons age 55 years or older have delirium
(13 percent in the age 85 years and older group in the com-
munity). Among elderly emergency department patients, 5 to
10 percent have been reported to have delirium. At the time of
admission to medical wards, between 15 and 21 percent of older
patients meet criteria for delirium-prevalent cases. Of patients
free of delirium at time of hospital admission, 5 to 30 percent
reported subsequent incidences of delirium during hospitaliza-
tion. Delirium has been reported in 10 to 15 percent of gen-
eral surgical patients, 30 percent of open heart surgery patients,
and more than 50 percent of patients treated for hip fractures.
Delirium occurs in 70 to 87 percent of those in intensive care
units and in up to 83 percent of all patients at the end of life
care. Sixty percent of patients in nursing homes or postacute
care settings have delirium. An estimated 21 percent of patients
with severe burns and 30 to 40 percent of patients with acquired
immune deficiency syndrome (AIDS) have episodes of delirium
while they are hospitalized. Delirium develops in 80 percent
of terminally ill patients. The causes of postoperative delirium
include the stress of surgery, postoperative pain, insomnia, pain
medication, electrolyte imbalances, infection, fever, and blood
loss. The incidence and prevalence rates for delirium across
settings are shown in Table 21.2-2.
Risk for delirium could be conceptualized into two catego-
ries, predisposing and precipitating factors (Tables 21.2-3 and
21.2-4). Current approaches to delirium focus primarily on the
precipitation factors and do little to address the predisposing
factors. Managing predisposing factors for delirium becomes
essential in decreasing future episodes of delirium and the mor-
bidity and mortality associated with it.
Table 21.2-1
Delirium by Other Names
Intensive care unit psychosis
Acute confusional state
Acute brain failure
Encephalitis
Encephalopathy
Toxic metabolic state
Central nervous system toxicity
Paraneoplastic limbic encephalitis
Sundowning
Cerebral insufficiency
Organic brain syndrome
